Helicopter



P. C. HEWITT.

HELICOPTER.

APPLICATION man IUNE 14, 1919.

Patented Aug. 24, 192% 4 SHEETS-SHEET l.

INVENTOR dam 'P. C. HEWITT.

HELICOPTER.

APPLICATION nun JUNE14, 1919.

Patented Aug. 24, 1920.

4 SHEETS-SHEET 2.

P. C. HEWITT.

HELICOPTER- APPLICATION nub mm, 1919.

Patented Aug. 2 1, 1920.

4 SHEETS-SHEET 3.

lNVENTOR m M W 'g -ATTOR EY6 P. C. HEWITT.

HELICOPTER.

APPLICATION FILED JUNE 14, 1919.

4 SHEETS-SHEET 4.

Patented Aug. 24, 1920.

INVENTOR @651 MM, Kim

@ATTQRNEN UNITED STATES.

PATENT OFFICE.

PETER COOPER HEWITT, 0F RTNGWOOD MANOR, NEW JERSEY.

HELicorTER.

Specification of Letters Patent.

Patented Aug. 24, 1920.

Application filed June 14, 1919. Serial No. 304,189.

To all cohom it may concern:

Be it known that I, PETER COOPER HEWITT,

a citizen. of the United States, and a resident of Ringwood Manor, Passaic, county,-

'- ,copter.

. One of the objects of my invention is to provide power transmitting means whereby a large'speed reduction is obtainable with smooth operation of the various parts.

Another object of the invention is to provide improved power transmitting means comprising gearing in which the rotation of the various gear members takes place without lateral thrust'or pressure on their bearings. In the improved gearing made according to this invention, the various gear members are acted upon by branched forces acting in opposite directions to produce true dynamic couples which cause little or no sidewise pressure or thrust on the bearings.

Other features, objects and advantages of my invention willappear more fully in the following detailed description and appended claims.

The accompanying drawings forming a part of this specification illustrate two enibodiments of my invention.

. In the drawings Figure 1 is a plan view of one embodiment of the invention;

Fig. 2 is a side elevation of the same;

Fig. 3 is a partial sectional view taken on line 33 of Fig. 1, but drawn on a larger scale and showing frame covering plates omitted from Fig. 1;

Fig. 4 is a central vertical sectional view of another embodiment of the invention;

Fig. 5 is a plan view of the same; and

Fig. 6 is a side elevation of the'same.

The invention is shown as arranged for driving two co-axial vertical shafts 1 and 2. These shafts, as shown, are the vertical shafts of the lifting and driving propellers (not shown) of a helicopter, one of the propellers being secured to each of the shafts, as shown more fully-in various co-pending applications filed by me on even date herewith. The shaft 1, as shown, extends through the tubular shaft 2, and the latter extends through a stationary tubular bearing 3 forming part of the frame 4 of the device. Motors or engines 5 and 6 of substant ally equal power are arranged, one on one side, and the other on the opposite side of the shafts 1 and 2, these motors or engines having their. driving shafts in axial alinement and arranged so that the axis of the driving shafts intersects the axis of the shafts 1 and 2 at right angles. The shaft of the engine 5 is connected as by a coupling 7 to the shaft 8 of the beveled pinion 9, and the shaft of the engine 6 is connected by a coupling 10 to the shaft 11 of the bev- ,eled pinion 12 (see Fig. 3), the axis of the pinions 9 and 12 being coincident with the axis of the engine shafts. Each of these pinions meshes with a large beveled gear 14 carried by'the shaft 2 above the pinions, and also with a large beveled gear 15 carried by the shaft 4 below the pinions. The two pinions 9 and 12 have the same number of teeth, as do also the two larger gears 14 and 15, the latter having a larger number of teeth than the former. 15 is formed with a rigid outer ring portion 16 having teeth meshing with the teeth of the pinions 9 and 12, the ring portion being supported by a flexible plate 17 which, at its iinner end, is secured to a hub 18 mounted upon the corresponding shaft 1 or 2. The plates 17 are desirably made of comparatively thin sheet metal, such as steel. The said gears 14 and 15 are accurately maintained in co-axial relation by suitable means such as a ball hearing which, as shown, comprises a runway 19 extending downwardly from the flexible plate 17 of the gear 14, a runway 20 extending upwardly from flexible plate 17 of the gear 15;, and balls or antifriction members 21 arranged between said runways and held properly spaced as by ring portion 27 held against displacement rela-' Each of the gears 14 and tively to the straps 25 by collars 28 and 29,

" an inner ball race member 30 held'in position between rings 31 and 32, an outer ball race member 33 and balls 34 arranged between the ball race members. As the structure is light, any warping or distortion of the. frame holding the gears and propeller shafts is taken care of and allowed for by reason of the flexible mounting of the gears 14'and 15, which, although yielding, must remain accurately in mesh with the pinions 9 and 12,,being held in place by the co-action of the rollers 24. Flexibility of structure combined with forced working accuracy of the parts of the power transmitting system Iconsider very important in the helicopter. Each of the pinions 9 and 12 is supported in proper position with respect to the frame by suitable bearings comprising, as shown, the-ball bearings 37 and 38 for holding the pinions in position .laterally of their axes. and the bearings 39 and 40 for taking thrust longitudinally of the axis of the pinions.

The lower ends of the shafts 1 and 2 are held in coaxial relation to each other and to the tubular member 3 forming part of the supporting frame by suitable antifriction bearings; and suitable anti-friction bearings are also provided to transmit the lift or weight of the propellers to the supporting frame. To this end the shaft 2 has securedthereon, as by brazing, a sleeve 42 on which are mounted in the order named a collar 43, sleeve 44, a second collar 45, a second sleeve 46, andthe hub 18 of the gear wheel 14. These parts are held in position longitudinally of the shaft 4 by means of anut 47, by which they are movable along a sleeve 42 until the collar 43 is locked against the projecting flange at the upper end of the sleeve 42. The hub 18 of the gear wheel is keyed to the shaft, preferably by a number of longitudinally arranged keys 48 arranged around the shaft. A thrust bearing comprising an upper ball race 49, a lower ball race 50 and a series of interposed balls 51, is arranged between the collars 43 and and a ball bearing comprising an outer ball race 52, an inner ball race 53, and a series of balls 54 interposed between said ball races, is arran ed between the collar 46 This last named ball hearing is designed to hold the shaft 2 in proper co-axial relation to the tubular frame member 3, and permit the free rotation of the shaft 2 within said member. The two ball bearings just described are inclosed within a casing 55,.which, as shown, extends downwardly from'and is integral with, a sleeve 56 surrounding the lower end of the member 33. The lower end of the casing 55 is closed, as by plate 57 which is bolted or otherwise secured to the body of the casing.

Any upward pull of the shaft 2 is transmitted through the hub 18 of the gear 14,

the sleeve 46, the collar 45, the thrust bearing 50, 51, 49', to the upper outer end portion of the casing 55. The thrust bearing 49, 50, 51, has a slight play between the collars 43 and 45 sothat, when the upper ball race 49 engages the casing 55, it will not be held tightly against the-collar 43 so as to bind the shaft 2, it being understood that the collar 43 rotates with the said shaft while the upper ball race member 49 is stationary.

When the machine rests upon the ground the weight of the shaft is transmitted to the frame through the projection at the upper end of the sleeve 42, the collar 43, the thrust bearing 49, 51, 50, the ring 55, and the outer ball race member 52 to the part 57 of the frame. The inner ball race member 53 has a slight play between the collar 45 and the hub 18 of the gear, so that when there is downward thrust of the shaft it will not be forced into binding engagement with the stationary plate 57. It will be seen that the bearings just described not only tend to hold the shaft 2 in proper relation to its support and permit free rotation thereof, but they also take the upward pull of the shaft as well as the downward thrust or weight thereof without causing binding of the bearings.

The bearings for holding the lower end of the shaft 1 in proper position in the supporting frame and for taking the upward just descri ed, and detailed description thereof is ft iought to be unnecessary. The bearings or shafts 1 and 2 are fully disclosed and are claimed in a co-pending application relating to helicopters filed by me on even date herewith.

The arrangement of gears described above is such that a balanced action is obtained in driving the shafts 1 and 2, and there is substantially no thrust on the various important bearings inasmuch 4 as each moving part through which there is a transmission of power, is acted upon by substantially equal forces acting in opposite directions. Each of the gears 14 and 15, for example, is acted upon on one side of its axis, by the pinion 9 tending to drive the same in one direction,

pull or the Height thereof, are like those for example, forwardly referring to Fig.

while on the other side of its axis it is acted upon by the pinion 12, tending to drive the same in the opposite direction, or rearwardly in the case assumed. In other words, a true dynamic couple is obtained causing rotation with no thrust upon the bearings. Likewise each of the pinions 9 and 12 is acted upon at diametrically opposite points by the gears 14 and'15 rotating in opposite directions, and the reaction of the gears 14- and15 exerts a turning tendency about the axis of the pinions 9 and 12 with little or no lateral thrust on the bearings of the pinions.

By reason of the construction and mount;

the efliciency or smooth action of the apparatus.

Inthe form' ofmy invention shown in Figs. 4, 5 and 6 the speed reduction is db- Y tained in two stages, while at the same time the balance of forces eliminating side thrust upon the gear bearings is maintained.- The apparatus also, as will be evident, is very compact.

Referring to Figs. 4, 5 and 6, the shafts of the engines 5 and 6 (not shown in these figures) are connected to drive the horizontal shafts 8 and 11 and pinions 9 and 12, the axis of shafts 8 and 11' being coincident with the axis of the driving shafts of the engines 5 and 6. The vertical shafts to'be driven are shown at 1' and 2, and 3' represents a tubular sleeve surrounding the shaft 2' and forming a part of the frame 60 of the apparatus. As-in the previously described form of my invention, the vertical shafts, as shown, are the driving shafts, respectively, of the upper and lower lifting propellers of a helicopter. Referring more particularly to Figs.- 5 and 6, the pinions 9'. and 12' mesh with gears 61 and 62 which are rotatable about a horizontal axis extending at right angles to the axis of the gears 9 and 12 and the shafts 1' and 2,-the gear 61 being 7 arranged to one side of the pinions and the gear 62 on the opposite side. The pinions 9 and 12' .have the same number ofteeth, as do also the gears 61 and 62; but the latter gears have a much larger number of teeth than the former.

The gears 61 and 62, as shown, are formed of an outer rigid ring portion meshing with the gears 9 and 12', each of the ring portions 61 and 62 being supported by flexible plates of conical form, these plates being desirably made of sheet'metal, such as steel. The flexible plate 63 of the gear .61 is secured at its inner end to a hub 65, and the flexible plate 66 of the gear 62 is secured at its inner end to the hub 67. The hub is secured to and adapted to drive the shaft 68 of a small beveled pinion 69, and the hub 67 is secured to and adapted to drive the shaft 70 of a small beveled pinion 71. The beveled pinions 69 and 71, which have the same number of teeth, are accordingly arranged to be rotated by gears 61 and 62,-respectively, about the axis of rotation of the said 65 gears 61 and 62. Each of the pinions 69 and 71 meshes with a larger beveled gear 72 secured to the shaft 2' above the pinions 69 and 71, and also with beveled gear 73 of the same size as the beveled gear 72, but secured to the shaft 1 below the pinions 69 and 71. The gears 72 and 73 have the same number of teeth, this number being considerably larger than the number of teeth on pinions 69and 71. There is oneangular speed reduction obtained between the pinions 9', 12, and the gears 61, 62, and another speed reduction obtained between the-pinions 69, 71, and the gears 72, 73. Accordingly a very large total angular speed reduction isobtainable while at the same time the device is very compact, and there is a balanced action on the various gear members producing true dynamic couples tending to rotate said members about their axes and thus causing no lateral thrust upon the bearings of said members. reduction gearing designed by me in accordance with this form of my invention there is obtained a total speed reduction of approximately 23 revolutions to one revolution.

Coacting with the flexibly mounted gears 61 and 62 to hold the same in mesh with the pinions 9' and 12 the frame 60 is provided with rollers 75 supported by means of antifriction bearings from the frame 60, and bearing against the inner peripheries of the rigid outer ring portions of the gears 61 and 62.. Rollers 90 bearing against the rear of the toothed portions of the gears 61 and 62 may also be used to insure meshing of the said gears with pinions 9 and 12. The

gears 72 and 73 are likewise provided with rigid outer ring portions having teeth meshing with the pinion engaged thereby, these rigid ring portions being supported by flexible plates 76, of sheet steel or the like, ex-

tending inwardly from said ring portions and secured at their inner edges to hub portions 77 connected to the respective shafts 1 and 2'. Coa'cting with these flexibly mounted gears for holding the same in mesh with the pinions 69 and 71, rollers 78 are provided. These rollers are supported in the frame 60 by means of ball bearings and bear against annular tracks 79 projecting respectively from the outer or rear. ,faces of the rigid ring portions of the gears 72 and 73.

For insuring a true axle alinement of the gears 72 and 73 a ball bearing is provided between the flexible plates 76 of said gears. This ball bearing, as shown, comprises an In one form of balanced double annular flange-like outer ball race 80 pro- The shafts 1' and 2' are held in operative relation with respect to the frame 60 as well as to the hubs 77 of the gears 72 and 73 by 'bearin means of connections and bearings like those described above in connection with the form of invention shown in Figs. 1, 2 and 3, and a detailed description of said connections and bearings is thought to be unnecessary. Briefly stated, the thrust of each of said shafts is transmitted through an antifricis a considerable degree of protection for the parts.

While I have shown two forms of my invention, it is to be understood that I am not limited to these forms, and that many modifications may be made without departing from the spirit of my invention.

What I claim as new and desire to secure by Letters latent, is:

1. In a helicopter, the combination of a propeller shaft, a driving gear, a gear driven thereby .and connected with said shaft, one of said gears being yieldably supported, and means co-acting with said last-mentioned gear to hold the same in mesh with the other gear. 2. In a helicopter, the combination of a propeller shaft, a driving gear, a gear driven thereby and connected with said shaft, one of said gears being yieldably supported and means co-acting with said last-mentioned gear to hold the same in mesh with the other gear, said yieldably supported gear comprising a rigid ring provided with teeth, and a flexible supporting plate extending inwardly from said ring and secured thereto.

3. In a helicopter, the combination of a pair of propeller shafts, a pair of driving gears and a pair of gears each driven by both of said driving ears, the gears of one of said pairs being yieldably mounted, and each one of said driven gears being arranged to drive a propeller shaft.

4. In a helicopter, the combination of a pair of propeller shafts, a pair of driving gears, a pair of gears each driven by both of said driving gears, the gears of one of said pairs being yieldably mounted, and

means co-acting with said last-named gears to hold the same in mesh with the other gears,.each one of said driven gears being arranged to drive a propeller shaft.

5. The combination of a pair of driving bevel gears having a common axis, a pair of bevel gears of larger diameter having a common axis at right angles to said firstnamed axis, each of said second named pair of gears being driven by both of said driving gears and being yieldably mounted, and means co-acting with said yieldably mounted gears for holding the same in mesh with said driving gears.

6. In ahelicopter, the combination of a pair of propeller shafts, a pair of driving members rotatable in opposite directions, a pair of members rotated thereby, each member of one of said pairs engaging respectively on opposite sides of its axis of rotation with the two members of the other pair, a third pair of members comprising a member rotating with each of said rotated members, and a fourth pair of members rotatable by said third pairof members, each member of said third and fourth pairs of members engaging two oppositely rotating members on opposite sides of its axis of rotation, said fourth pair of members being connected respectively with said shafts to drive the same. 7. The combination of a pair of driving members rotatable in opposite directions, a

pair of members rotated thereby, each member of one of said pairs engaging respectively on opposite sides of its axis of rotation with the two members of the other pair, a third pair of members comprising a member rotating with each of said rotated members, and a fourth pair of members rotatable by said third pair of members, each member of said third and fourth pairs of members engaging two oppositely rotating members on opposite sides of its axis of rotation.

- 8. The combination of a pair of driving gears rotatable in opposite directions, a pair of gears driventhereby, each gear of one of said pairs meshing respectively on opposite sides of its axis of rotation with the two gears of theother pair, a third pair of gears comprising a gear rotating With each of said driven ears, and a fourth pair of gears driven by sa1d third pair of gears, each gear of said third and fourth pair of gears meshing with two oppositely rotating gears on opposite sides of its axis of rotation.

9. In a helicopter, the combination'of a pair of propeller shafts, a pair of driving gears rotatable in opposite directions, a pair of gears driven thereby at reduced angular velocity, each gear of one of said pairs meshing respectively on opposite sides of its axis of rotation with the two gears of the other pair, a third pair of gears comprising a gear rotating with each of said driven gears, and a fourth pair of gears driven by said third pair of gears at reduced angular velocity, and connected respectively to said shafts to drive the same, each gear of said third and fourth pair of gears meshing with two oppositely rotating gears on opposite sides of its axis of tion.

rota- 10. The combination of a pair of driving gears rotatable in opposite directions about a common axis, a pair of gears driven thereby about an axis at right angles to said first named axis, each gear of one of said pairs meshing respectively on opposite sides of its axis of rotation with the two gears of the other pair, a third pair of gears comprising a gear rotating with each of said driven gears about the axis thereof, and a fourth pair of gears driven by said third pair of I gears about an axis at right angles to both of the aforementioned axes, each gear of said third and fourth pair of gears meshing with two oppositely rotating gears on opposite sides of its axis of rotation.

11. In a helicopter, the combination of a pair of propeller shafts, a pair of driving gears rotatable in opposite directions, a pair of gears driven thereby, each gear of one of said pairs meshing respectively onopposite sides of its axis of rotation with the two gears of the other pair, a third pair of gears comprising a gear rotating with each of said driven gears, a fourth pair of gears driven by said third pair of gears and connected respectively with said shafts to drive the same, each gear of said third and fourth pair of gears meshing with two oppositely rotating gears on opposite sides of its axis of rotation, and means co-acting with said gears to hold the same in mesh.

12. The combination of a pair of driving gears rotatable in opposite directions, a pair of gears driven thereby each gear of one of said pairs meshing respectively on opposite sides of its axis of rotation with the two gears of the other pair, a third pair of gears comprising a gear rotating with each of, said driven gears, a fourth pair of gears driven by said third pair of gears, each gear of said third and fourth pair of gears meshing with two oppositely rotating gears on opposite sides of its axis of rotation, and rollers co-acting with said gears to hold the same in mesh.

13. The combination of a pair of driving members rotatable in opposite directions, a pair of members rotated thereby, each member of one of said pairs engaging respectively on opposite sides of its axis of rotation with the two members of the other pair, a third pair of members comprising a member rotating with each of said rotated members, a fourth pair of members rotatable by said third pair of members, each member of said third and fourth pair of members enother as aforesaid.

14. In a helicopter, the combination of a pair of propeller shafts, a pair of driving members rotatable in opposite directions, a

pair of members rotated thereby, each member of one of said pairs engaging respectively on opposite sides ofits axis of rotation with the two members of the other pair, a third pair of members comprising a member rotating with each of said rotated members, a fourth pair of members rotatable by said third pair of members and connected respectively with said shafts to drive the same, each member of said third and fourth pair of members engaging with two oppositely rotating members on opposite sides of its axis of rotation, the members of one of said first two pairs and also the members of one of said last two pairs being-yieldably mounted, and means co-acting with said members to hold the same in engagement with each other as aforesaid. I

15. In a helicopter, the combination of a pair of gears rotatable about a common axis, co-axial propeller shafts yieldably supporting the-respective gears, and means co-acting with said gears for insuring their axial alinement. v

16. In a helicopter, the combination of a pair of gears rotatable about a single axis, each of said gears comprising a rigid ring and a flexible supporting plate extending inwardly from said ring, a propeller shaft to which each of said plates is connected, and

means co-acting with said plates for insuring.

the axial alinement and meshing of said ears.

1?. The combination of a pair of gears rotatable about a single axis, co-axial shafts -for the respective gears, each of said gears comprising a rigid ring and a flexible supporting plate extending inwardly from saidring and connected with one of said shafts, and an antlfriction bearlng co-actlng w1th said plate .for insuring the axial alinement 18. The combination of a pair of gears rotatable about a single axls, co-axlal shafts for the respective gears, each of said gears comprising a rigid ring and a flexible supporting plate extending inwardly from said ring and connected with one of said shafts, an antifriction bearing co-acting with said plates for insuring the axial alinement of said gears, said bearing comprising an annular projection extending from each of said plates and rolling members between said projections, gears meshing with said first named gears, and means bearing against said first named gears for holding the same in mesh with said second named gears.

19. In a helicopter, the combination of a hollow casing including a rotatable inclosing member, speed reducing gearing inclosed by said casing and driven thereby, and a propeller shaft driven by said gearing.

20. In a helicopter, the combination of a said gears, speed reducing gearing inclosed casing comprising a pair of gears coacting and driven by said pair of gears and comto form a hollow casing, means for driving prising a pair of driving gears and a pair said gears, speed reducing gearing inclosed of gears each .driven by both of said driving 5 and driven by said pair of gears, and progears, and a propeller shaft driven by each 15 peller shafts driven by said speed reducing of said driven gears.

gearing. In testimony whereof I have signed my 21. In a helicopter, the combination of a name to this specification. casing comprising a pair of gears coacting 10 to form a hollow casing, means for driving PETER COOPER HEWITT. 

